AVB Revels in New Van der Vaart Signing

Having previously signed a pre-contract agreement with Spurs, Holtby has joined the club on a permanent basis in January, as cover for injured midfielder Sandro.

Holtby could make his debut for Tottenham in the Premier League trip to Norwich, and Villas-Boas is hoping his side can benefit from a player who in his eyes is one of the bargains of the century.

Villas-Boas may attempt to sign one more striker.

"Is he the bargain of the century? I think so because it's difficult to find a young player who is running his contract down and we faced tough competition," Villas-Boas said.

"He's recognised as an exceptional young talent and we have high expectations of the player.

"Because of his creativity you can compare him to Rafa [van der Vaart] - to a certain extent anyway because Rafa was a greatly experienced player when he joined and Lewis has all his career ahead of him.

"He will fill the No.10 position, although he can play on the right or the left and he has also played in a holding role."

With Emmanuel Adebayor still away on African Nations Cup duty, as his Togo team side hunt down a place in the quarter-final where they need just a draw in their final group game against Tunisia, and Jermain Defoe struggling with a hip problem, Villas-Boas is under pressure to add an attacker to his squad for the January transfer window shuts on Thursday.

Having previously resisted in making such a move in the window, Villas-Boas finally having switched permanently to 4-4-2 formation, Tottenham may look to sign an additional forward on deadline day.

Tottenham have consistently been linked with a move for Brazilian striker Leandro Damiao, but are yet to agree a deal for the London 2012 Olympic Games' top scorer.

"We've found consistency in 4-4-2 so eventually we have the possibility to have one more [striker]," Villas-Boas added.

"It's just trying to see if it makes sense. The January market is very demanding. Transfer fees can be ridiculously high."